A nucleotide consists of which components?

A nucleotide consists of which components?

• A. Phosphate group, sugar, and nitrogen base
• B. Phosphate group only
• C. Sugar only
• D. Nitrogen base only

Answer: (A)

Nucleotides are built from three parts: a phosphate group, a sugar, and a nitrogen base. The sugar (deoxyribose in DNA or ribose in RNA) forms the backbone together with the phosphate; the nitrogen base sticks off the sugar and stores genetic information by pairing with its complement on the opposite strand. The phosphate group is what links nucleotides together through phosphodiester bonds, creating the long sugar–phosphate chain that makes up the backbone of the nucleic acid. If you only had one part—phosphate, or sugar, or a nitrogen base—you wouldn’t have a complete nucleotide, but just a component. That’s why the full nucleotide includes all three components: phosphate group, sugar, and nitrogen base.

Nucleotides are built from three parts: a phosphate group, a sugar, and a nitrogen base. The sugar (deoxyribose in DNA or ribose in RNA) forms the backbone together with the phosphate; the nitrogen base sticks off the sugar and stores genetic information by pairing with its complement on the opposite strand. The phosphate group is what links nucleotides together through phosphodiester bonds, creating the long sugar–phosphate chain that makes up the backbone of the nucleic acid. If you only had one part—phosphate, or sugar, or a nitrogen base—you wouldn’t have a complete nucleotide, but just a component. That’s why the full nucleotide includes all three components: phosphate group, sugar, and nitrogen base.